In unloading bulk material--for instance ore, grain, or coal--from a bulk carrier such as a barge it is standard to pull the ship up adjacent a dock provided with a conveyor system having a vertically effective conveyor that is lowered by a crane arrangement right into the hold to scoop up and carry away the bulk material. French patent 2,217,250 of Riboulet, U.S. Pat. No. 4,732,523 of Antikainen, European application 0,039,487 of Straub, and German patents 2,523,948, 3,704,392 of Fritsch, 3,802,420 of Grathoff, 3,913,359 of Grathoff, 4,121,996 of Grathoff, and 4,135,467 also of Grathoff all disclose systems where a dock-mounted support has an upper end on which is pivoted an elongated arm or boom whose outer end is provided with a vertically effective bucket or skip conveyor whose lower end is constituted as an intake. The arm is pivoted on the upper end of the support and the conveyor is in turn pivoted on the outer end of the arm so the conveyor can be moved up and down by pivoting of the arm. Frequently the support is constituted as a turntable and/or carriage so that the support and the arm can be moved to sweep the intake along the hold of the ship being emptied.
Such an arrangement cannot frequently reach all the corners of the hold, so that equipment must be employed to push the bulk material out to where the intake can get to it. Furthermore maneuvering the vertical conveyor so as to avoid various structures on the ship is also a problem with the known systems.